Reward influences movement vigor through multiple motor cortical mechanisms.

Area of Science:

• Neuroscience
• Motor Control
• Decision Making

Background:

• The prospect of higher rewards often increases movement vigor.
• Understanding the neural basis of this reward-driven vigor modulation is crucial for comprehending motivated behavior.

Purpose of the Study:

• To investigate the neural mechanisms in the motor cortex that translate reward magnitude into movement vigor.
• To identify specific neural activity patterns associated with reward-modulated movement vigor.

Main Methods:

• Three rhesus monkeys performed reaching movements towards targets with varying reward values.
• Neural population activity was recorded from the primary motor cortex and dorsal premotor cortex during the task.

Main Results:

• Specific neural activity features during movement preparation, initiation, and execution correlated with movement vigor and were modulated by reward.
• Neural metrics for different aspects of movement vigor showed limited correlation, suggesting multiple underlying mechanisms.
• A significant portion of reward's modulation on motor cortical activity was independent of behavioral vigor changes.

Conclusions:

• Reward significantly modulates neural activity in the motor cortex, influencing movement vigor.
• Multiple neural mechanisms contribute to how reward enhances movement vigor.
• Motor cortical activity modulation by reward may serve functions beyond simply increasing movement vigor.